Push lock switch

Abstract

A push lock switch having a lock mechanism for use as a hazard switch or a rear defogger switch on an instrument panel of an automobile. The switch has first and second stationary members assembled together which define a space into which a movable member is slidably fitted. A push button fits over the movable member. A coil spring is mounted between the movable member and the first stationary member. The coil spring has first and second compression parts in a one piece construction with each other and urges the movable member toward the push button. A movable contacting strap is fixed to the movable member. The movable contacting member includes movable contacts and a retainer. The movable contacts slide into or out of contact with fixed contacts on the second stationary member when the movable member is pushed by the push button. The first stationary member has a bottom wall in which a recess is formed and on which a plurality of ribs are formed on the recess. A pin rises from the bottom wall of the recess to engage the engagement groove in a heart cam so as to pivotally support the heart cam. The heart cam is formed with a cam groove of a predetermined shape which is engaged with a lock pin inserted into the movable member, thereby providing a push lock mechanism.

What is claimed is: 
     
       1. A push lock switch having a lock mechanism for locking a movable member, the movable member moving relative to a stationary member so as to cyclically open and close a switch each time the movable member is pushed, the push lock switch comprising: a heart cam pivotally mounted to the stationary member; and   a lock pin mounted to the movable member and urged toward said heart cam to engage said heart cam;   wherein said movable member is adapted to extend from and retract into the stationary member; and   wherein the movable member includes a movable contacting strip having a movable contact and a retainer for retaining said lock pin, said movable contact being in a one piece construction with said retainer.   
     
     
       2. A push lock switch having a lock mechanism for locking a movable member, the movable member moving relative to a stationary member so as to cyclically open and close a switch each time the movable member is pushed the push lock switch comprising: a heart cam pivotally mounted to the stationary member; and   a lock pin mounted to the movable member and urged toward said heart cam to engage said heart cam;   wherein said movable member is adapted to extend from and retract into the stationary member; and   wherein the movable member further includes biasing means having a first compression part in the form of a closely wound coil spring and a second compression part in the form of a loosely wound coil spring, said first and second compression parts being in a one piece construction with each other.   
     
     
       3. A push lock switch having a lock mechanism for locking a movable member, the movable member moving relative to a stationary member so as to cyclically open and close a switch each time the movable member is pushed, the push lock switch comprising: a heart cam pivotally mounted to the stationary member; and   a lock pin mounted to the movable member and urged toward said heart cam to engage said heart cam;   wherein said movable member is adapted to extend from and retract into the stationary member; and   wherein the stationary member includes a plurality of molded sections each of which is insert-molded from a resin material with a conductive plate therein, at least one of said conductive plates having a caulking strap in a one piece construction with said conductive plate, and the plurality of molded sections being assembled together by caulking using said caulking strap.